HEPA Air Purifiers

Air purifiers have become an important part of the modern society, due to the environmental situation. HEPA filters are the most popular, efficient and reliable filter, used in the air purification and it remains the most efficient filter for over a half of the century. They were originally designed in the 1940th and used in the Manhattan Project to prevent the spread of radioactive contaminants. HEPA filters were commercialized in the 1950th and the original term became a registered trademark and generic term used to describe highly-efficient air filters. Since that time the filters have been improved, but still their basic design and function remained the same.

HEPA or High-Efficiency Particulate Air filters are a widespread tool, used in many mechanical air cleaners to filter small and unhealthy pollutants out of the air. They consist of a web of fibers and operate in a different way, in comparison with membrane filter. HEPA technology includes three stages: interception, impaction and diffusion. At the interception stage particles, which are above 0.4 microns, stick to one of the fibers, after getting close to it. Impaction stage affects 0.4 microns pollutants, which are forced into contact with a fiber by the air stream path in which it is traveling, and is embedded into it. The diffusion stage is the result of gas molecules and smallest contaminants' collision. At this stage particles are impeded and delayed in their path through the filter and this behaviour is similar to Brownian motion. In diffusion mechanisms particles, which are below 0.1 microns, are affected.

The effectiveness of HEPA filters was discussed by United States Environmental Protection Agency and they were defined as the most efficient filters, which are widely used in mechanical air purifiers. A usual MERV (Minimum Efficiency Reporting Value), which represents purifiers' ability to clean air, of standard filters is somewhere between 1-16, while HEPA filters have 17-20 ratings. These filters have minimum efficiency between 99.97 and 99.999% in removing 0.3 microns particles. But still there are some disadvantage in HEPA filters and the main of them is the cost-efficiency of the devices. HEPA are replaceable filters and so you will have to buy the interchangeable filters. Another disadvantage is hidden in the name of the filter, as “P” in the name stands for “Particulate”. HEPA filters are not efficient against smoke, odors, gases or fumes. So if you are looking for an air purifier that will remove odors or smoke, then HEPA cleaners won't provide you with the necessary features.

If you are looking for an efficient and reliable air purifier that will guarantee maximum results, then HEPA cleaners are a good choice for you. These units are efficient against bacteria, viruses, mold spores, pet dander, dust and other air pollutant, but they don't remove odors, gases, smoke or chemicals, so this fact should be considered, before the purchase. HEPA purifiers are offered in a wide range, so each of the customers can choose the right appliance for him and his family.